Now that's interesting. Few thoughts:
1. Can you be more specific about the artifact skepticism?
The question is whether they may be geofacts. If the ones pictured in the article are the best they have, out of a total of around 20, it's a fair question.
2. Assuming it's real & it's about 1.6Ma, I think this has interesting implications about the initial Out of Africa expansion. It seems clear between this & Dmanisi that the earliest people in Europe did not have Acheulean technology. This leads me to two questions:
A. Is the Acheulean really that superior to the Oldowan, in terms of straight up functionality? People have kicked around the idea that the handaxe might have been more important in terms of social interactions (i.e. the big handaxes as signs of competence/sexiness/whatever). I don't know enough about archeology to answer this question.
I think we have to answer this with reference to the mechanism that causes Acheulean artifacts to be so widespread and persistent. This means not only bifaces but also aspects of procurement and other element of artifact reduction. It's easy to see why Oldowan is widespread and persistent: If you can maintain the idea of stone tools, knocking flakes off rocks, you've got Oldowan.
But why bifaces? One possible answer is the same as the Oldowan -- they're really quite obvious. But if they were so obvious and easy, why didn't anybody make them earlier?
My preferred explanation: They were functionally valuable, not too difficult, and were therefore recurrently invented again and again. This is the explanation for the fire drill in recent contexts -- independent invention. The test is whether there are non-biface aspects of the Acheulean that are too persistent to be compatible with independent invention. I don't know. Some obvious objections: If bifaces were so good, why were they ultimately replaced most everywhere? And why didn't they use them more often in East or Southeast Asia?
Bifaces could be easier than we might suspect for another reason: Maybe there were genetic biases maintaining them.
B. If the Acheulean is simply better technology, were humans really spread so thinly on the landscape at this time that they couldn't transmit a better technology across continents? If they were, it certainly highlights the appropriateness of source/sink models of human expansion out of Africa.
I agree. The question is how hard were they to transmit? If we knew, we could say much about the demography.
3. Assuming the site is legit & the Acheulean is plain better, does this have implications for the Out of Africa 2/Replacement model? The linchpin of that is that better technology allowed modern humans to once again expand out of Africa & replace the archaic peoples. But if ancient humans could expand out of Africa initially with nothing more than pebble tools, doesn't that seem to mitigate the logic of advanced technology facilitating a later expansion & replacement? Maybe the two out of Africa events are apples & oranges & this comparison simply isn't valid. (That is there was no one to outcompete initially, relative success is not a factor for the initial expansion.)
4. Makes you wonder what else is in Europe at this early age.
Don't forget Sima de Elefante. It's not as old, but it already raises many of the same questions. Was early European occupation constant? Was it an expansion out of Africa or Asia? Was it predictable as a consequence of Homo's ecology, or did it depend on some unique climatic conditions?
5. Imagine they find hominin fossils. How much would you bet they're similar to the Dmanisians?
Not too long ago, we had two options -- they were like Ceprano, or they were like Gran Dolina. Now Ceprano looks a lot less likely. And Gran Dolina, which gives us basically a face, isn't so awfully different from the Zhoukoudian faces. How hard would it be to derive these from Dmanisi? On the other hand, what do we know about the faces Africans after 1.5 million years ago? We've got OH 12 and Buia.
Of course, we might predict that faces should be extremely variable, considering that the mandibles are. I'll be writing something about KNM-ER 1482 before long, which strikes me as an interesting case.